Atmospheric sounding apparatus



F'Ipeloa KISS BEEBENCEf-fifg July 22, 1952 v. D. HAUCK ET AL ATMOSPHERIC SOUNDING APPARATUS Filed March 5, 1948 2 SHEETS-SHEET l gmc/wim',

VERNON D. HAUCK WILLIAM L.. VV. CDC-EDEN JAMES F? COSBY n moy U65 Ao ,a .W l w m 5 DLR 5, m NUMS 4 G G NAE V a, s 1 M T 2 m F WM S W L. 2 niv NU S www., m ii. :i A P NT G N @Qn K M R? ,C N @dus U w A s Z w Fu. H m 3 s R W, E f D.. m 10 m 5 M .V f q 2 cz.. l. u w :l w n M 2 laf 5 5.. w w h y m 7, 2 A 2 m ,.v.. uw F Patented July 22, 14952u amsn ATMOSPHERIC SOUNDING APPARATUS Vernon D. Hauck, Towson, William L. W. Ogden, Baltimore, and James R. Cosby, Towson, Md., assignors to Bendix Aviation Corporation, Baltimore, Md., a corporation of Delaware Application March 3, 1948, Serial No. 12,866

This invention relates toradio apparatus and, more particularly, to radio telemetering transmitters adaptedior operation within a substantially closed container.

Radio telemetering -apparatus has for4 some years been employed for transmitting automatically taken observations from the upper reaches of the atmosphere to ground stations employed for the collection of this data. The sounding devices, technically known as radiosondes, must be transported often vast distances to the point of observation. Frequently, especially in oonnection with military maneuvers, such points are located in rather inaccessible areas', making itV highly desirable to minimize the size, weight, and number 'of necessary accessories for the radiosonde transmitter. In addition, the fact that such atmospheric sounding devices are usually borne aloft by balloons makes it-desirable that their weight be held to a minimum.

Accordingly, it is an object of the present invention to provide new and novel radio transinitting apparatus of limited dimensions.

It is a further object of the invention to provide a sealed demountable rigid antenna which may be packed within the housing of the radiosonde for shipment.

Yet another object of the invention is to pro- 8 Claims. (Cl. Z50-2) vide atmospheric sounding apparatus most ef-`VV iiciently utilizing a limited volume.

Other objects and advantages of the invention will in part be disclosed and in part be obvious when the following specication is read in conjunction with the drawings in which: A

Fig. 1 is an elevation View, partly cut away and partly in section, illustrating the interior arrangement of van atmospheric sounding device incorporating the advantages of the invention;

Fig. 2' is a bottomview of this sounding device;

Fig. 3 is a plan view of the transmitter and modulator -chassis assembly;

Fig. 4 is an end view of this assembly;

are connected by a duct 26 passing .in anessens tially diagonal manner through the body of the4 housing. Temperature responsive resistor 22 and clips 24,.for the mounting of a hygroscopic reelstor, are mounted within this duct in a: position.;

exposing them to the ow of air induced in the duct .by the upward 'passage of the container l0 f through the atmosphere under the Viniiuence of the lifting balloon attached to the ring I4.' The duct 2B divides the container into two por tions, the barometric chamber 26 lying above and to the right of the duct 20, Whilethe transmitter and battery chamber 28 lie below and tothe left of the duct.

'In the barometric chamber 26 there is located ,1A a pressure-actuated switch 29 which may be oi" the type shown in U. S. Patent 2,437,473, issuedin the names of William L. W.'Ogden andWilliam R. Ryan. This switch is provided witha` cable 3B whose component conductors are'connected to appropriate terminals of the modulator portion of the transmitter. The cable 32 leading from the measuring element assembly '34 is similarly connected. Before a ight, the pres.4 sure switch 29 is adjusted tothe local pressure level by opening the door Il in the case IU.. The transmitter chamber 28 houses the transmitter assembly 36 andthe battery 38 whichis located within the smaller portion of the transf mitterchamber 28 substantially. directly underneath the supporting strap i2. A power cable 40 connects the battery 38 with the transmitter as- ,z

-sembly 36.' The transmitter 36 is further pro-z Fig. 5 is a side View showing the details of the transmitter chassis assembly; and

Fig. 6 illustrates the mechanical adjustment used for the control of the transmitter frequency.

Referring now to the drawings, Fig. l illustrates an enclosure i6 which may be of fiberboard, cardboard, or other suitable material. A strap I2 is stapled near the upper surface of this container and provided with a ring I4 to which the lifting balloon may be attached. The container I0 is provided with-openings I6 and i8 in its upper and lower surfaces, respectively, which vided with a terminal strip 42to accommodate connection of the leads from the cables 36 and 32. The radio frequency energy from the radio transmitter assembly 36 is radiated from the relatively rigid antenna 44 projecting through the opening 46 in the case I0 into the trans.- mitter assembly 36. A cork or other sealingplug 48 slideable upon the antenna d lits snugly withe in the aperture 46' to prevent thev entrance of rain, etc.

This equipment encounters severe cold at very high altitudes, and such a drop in temperature would diminish greatly the power available from the battery 33. To prevent this, the transmitter assembly 3B and .battery 38 are enclosed together within a layer of insulation 50. This insulation prevents the loss of heat from the transmitter A chamber, thus tending to keep the battery Warm and also coniines within this volume the heat de- An adjusting screw 52, accessible through a slot H in one of the edge walls of the transmitter assembly 35, provides for adjustment of the radiated frequency on the ground prior to release of the instrument.

The details of the transmitter assembly 3G may be most readily comprehended by an inspection of Figs. 3, 4, 5 and 6. The plan view of Fig. 3 displays the modulator chassis 54 and transmitter chassis 56. The chassis are separately formed of sheet metal and independently processed as sub-assemblies, after which they are secured together into a permanent final assembly by means to be disclosed in detail.

The modulator chassis 54 carries circuits designed to translate the changes in resistance of the measuring elements into a variable frequency employed for the modulation of the radio frequency transmitter. It includes a vacuum tube 58 and relay 60 together with terminals 42 to which the various connections from the meas-1 uring elements lead. The circuits of the modulator-translating unit, while not material to the present invention, may be found in the cepending U. S. application of James R. Cosby, Serial No. 771,200, led August 29, 1947, which matured into Patent No. 2,558,343, June 26, 1951.

The mechanical configuration of the modulator chassis is, however, of interest. The material-of the chassis 54, as well as that of 55, may be zinc, cadmium-plated steel, or other easily solderable material. The chassis 54 has a depending wall 62 at either end with an upstanding wall 64 along the outer edge. The imier edge is cut away at 56 and provided with an upright tongue 68 at the border of the cut-away portion, which enables the chassis 54 to be placed upon the Work bench in a stable inverted position with all circuit elements maintained out of contact with the supporting surface. The depending walls E2 are provided with projecting tongues IllV adapted for insertion in retaining straps 12 struck out of the end wall 14 of the transmitter chassis 56. The tongues may be secured in this position by soldering, welding. or other suitable means.

The transmitter chassis 56 may be of the same material as the modulator chassis and has substantially the form of a box with an open bottom. The volume, defined by the depending Walls 14, 1B, 18 and 80 of the transmitter chassis 55, houses a resonator line consisting of a pair of spaced conductive lines 82 and 34 running fairlyclose and parallel to the walls 16, 'i8 andll partially encircling the volume bounded by said Walls.. An electric discharge. tube 86 is situated Within the loop formed by the resonant lines 82 and 84, and may have its anode and grid terminals connected to one end of the respective lines near the center of the wall l5. The other end of lines 82 and 84 terminates adjacent the end wall 14 which is provided with a slot-like aperture 88 best seen in Fig. 4. This end of line 84 is provided with an enlarged portion 90 having a tapped aperture 92 which is tapped with a thread adapted to receive the threads on the inner end of antenna rod 44.

The lines 82 and 84 have an electrical length which is somewhat less than a half wave length at the radio frequency generated, due to the loading of the tube 86. However, because of the looped line configuration, it is not necessary that the maximum dimension of the transmitter chassis 56 approach this value. and the location of the tube 86 within the line loop provides an oscillator of great efficiency and stability. The lines 82 and 84 are lightly grooved at the nodal points most favorable for the introduction of supply potentials. This groove is most clearly shown in Fig. 5 where there is seen the groove S3 in. the line conductor 82. A similar groove, invisible in this view, is provided in the line 84 and the isolating chokes 94 and 9B connect the power supply terminals with the resonant line.

The line elements 82 and 84 are secured to the walls of the transmitter chassis 56 by the standofi bushings 98 cooperating with the clamp bars 100.

The radio frequency delivered by the oscillator is controlled by varying the capacitive endloading on the lines 82 and. 84 at a point not far removed from the wall 14. Near this end a pair of capacitor plates |02 and |04 are secured to the lines. The line 84 is flattened, pierced and tapped at 10E adjacent the end of the capacitor plate (04. A correspondingly threaded screw 52 in the aperture at |06 may be rotatably advanced or withdrawn to vary the spacing between capacitor plates |02 and 04 for exerting the desired control over the delivered frequency. The frequency adjusting screw 52 is accessible through an adjacent aperture l08 in the transmitter chassis 56, and an aligned slot H0 (Fig. l) in the wall 54 of the modulator chassis 54.

The illustrated radio frequency oscillator is of the type having a frequency determined by the half wave resonant line 82. 84 and designed to vend-feed a half wave rod antenna. Power is supplied to the oscillator circuit through the isolating chokes 94 and S6, while the cathode is connected to a ground strap H2 through a further isolating choke H4. This oscillator. it will be seen, is of the type in which input and output circuits are coupled, and the manner in which it generates sustained oscillations is well known and will not be discussed in detail here.

The assembly which has been illustrated and described is a highly compact measuring and telemetering transmitter. It is usually shipped without the battery 38 but with the antenna rod 44 and cork 48 inserted into the battery space. When the instrument is to be placed in use, this antenna is removed and its end threaded into the aperture 92 of the resonant line 84 after which the cork 48 is slid along the antenna rod 44 until it seats rmly in the aperture 45, thereby securely sealing the interior of the transmitter chamber 28 against the entrance of deleterious foreign substances. Thereafter the battery 33 is inserted and the power plug at the end of cable 40 seated in its socket. This places the transmitter in operation. The radio frequency may then be adjusted to the desired value for avoiding interference in the service area using a long screwdriver, passing through the slot I l0 and the aperture 108 and engaging the head of screw 52. When this has been done, the pressure switch 29 is adjusted through the door l l and the instrument may then be released. the hygroscopic resistor having been previously inserted in the clips 24. The location of the supporting strap l2 very nearly above the battery 38, which is the heaviest single unit of the assembly, insures that the instrument will rise in substantially level position under the influence of the lifting balloon attached to the ring I4.

The foregoing has made the essence of the in vention clear and there will be apparent to those skilled in the art many modifications and applications which do not distinguish substantially therefrom.

What is claimed and desired to be secured by United States Letters Patent is:

l. In signal radiating apparatus, a closed container of prismatic form, an air duct extending between opposite surfaces of said container dividing said container into two parts, measuring elements situated in said duct, a barometric switch located in one of said container parts, a modulating unit and transmitter with battery located in the other of said container parts, said modulating unit and transmitter being adjacent a corner of said container with said battery located more centrally of said container, means connecting said modulator, said measuring elements and said barometric switch, and means for radiating electrical energy from said transmitter.

2. In signal radiating apparatus, a closed atmosphere permeable container of prismatic form, an air duct extending diagonally between top and bottom surfaces of said container dividing said container into two parts, measuring elements situated within said duct, a barometric switch suspended from the top surface of said container located in one of said container parts, a modulating unit and transmitter with battery located on the bottom surface Within said container, said modulating unit and transmitter being located adjacent an end surface with said battery located more centrally of said container, means connecting said modulator, said measuring elements and said barometric switch, means extending through said container bottom surface for radiating electrical energy from said transmtten, andia supporting member secured to saidcontainer near said top surface along a line extending through said battery.

3. In signal radiating apparatus, a closed container of prismatic form, an air duct extending between opposite surfaces of said container dividing said container into two parts, measuring elements situated in said duct, a barometric switch located in one of said container parts, a modulating unit and transmitter with battery located in the other of said container parts. said other of said container parts having insulating material adjacent its inner surfaces, means connecting said modulator, said measuring elements and said barometric switch, and means for radiating electrical energy from said transmitter.

4. An improved radiosonde, comprising a closed box, an air duct extending diagonally between the top and bottom surfaces of said box and dividing said box into two compartments, said duct opening into the top surface at one end of said box and opening into the bottom surface at the other end of said box; a barometric switch located in one of' said compartments; a modulating unit and transmitter with battery located in the other of said compartments; measuring elements situated in said duct; means connecting said modulator, said measuring elements and said barometric switch; and means for radiating electrical energy from said transmitter.

5. The combination defined in claim 4, wherein a door is located in the end wall of said box in proximity to said barometric switch, whereby access may be had to said switch for purposes of adjustment.

0. The combination defined in claim 5, wherein said transmitter includes a pair of resonant lines terminating at a point in proximity to an opening in the bottom surface of said box, one of said lines having its extremity in the form of a threaded socket, and said radiating means comprises a rod-like antenna having a threaded extremity for cooperating with said threaded extremity of said line.

7. The combination defined in claim 6, wherein sealing means are provided in the opening in said bottom surface surrounding said antenna.

8. The combination defined in claim 4, wherein said transmitter includes a pair of resonant lines having a pair of capacitor plates located between said lines near the outer extremity thereof, said plates being relatively movable to change their spacing and thereby control the radio frequency of said transmitter, means are provided for moving said plates, and an opening is provided in said box for actuating said last-named means.

VERNON D. HAUCK. WILLIAM L. W. OGDEN. JAMES R. COSBY.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date .2,126,541 De Forest Aug. 9, 1938 2,175,025 Hoeven Oct. 3, 1939 2,180,107 Hathaway Nov. 14, 1939 2,192,711 Lindenblad Mar. 5, 1940 2,278,531 Buachbeck Apr. 7, 1942 2,288,294 Morelock June 30, 1942 2,292,254 Van Beuren Aug. 4, 1942 2,300,617 Crowley Nov. 3, 1942 2,310,017 Cannon et al Feb. 2, 1943 2,337,987 Galloway Dec. 28, 1943 2,347,160 Wallace Apr. 18, 1944 2,347,345 Wallace Apr. 25, 1944 2,354,086 Mackay July 18, 1944 2,440,308 Storck Apr. 27, 1948 2,444,189 Finneburgh et al. June 29, 1948 

